Heavy-duty swab



May 6, 1930- G. CHRISTENSON AHEAVY DUTY swAE Filed April 18, 192s Patented May 6, 1936 i lsra'rls vPA'r-lezN'r OFFICEA GEORGE cHRIaTENsoNl OE NORTH PLAINEIELD, NEW lJERSEY, AssIGNoR To JOHNS- MANVILLE CORPORATION, OE NEW YORK, N. Y., A CORPORATION OE NEW YORK v HEAVY-DUTY SWAB Application led April 18,

This invention relates to heavy duty swabs and to packing therefor, and particularly to devices of this character suitable for oil wells or similar locations, wherein it is necessary to provide a substantially fluid-tight seal under great pressures and despite irregularities in the wall. of the'conduit which is engaged by thel swab. Tubular well casings, when carried to a considerable depth, are ordinarily characterized .by irregular surfaces which are adapted to abrade and seri- `ously injure the swab cups or packmg elements which engage them. Furthermore, it is particularly diiicult to maintain the packing in proper engagement with walls of th1s character, since the 'clearance space about the packing varies and the wall itself rough and irregular. y The present invention is designed to afford a longer-lived and more effective swab for this purpose, particularly providing a packing Or swab cup arrangement which is adapted to withstand the unusually severe abrasive action, blows and stresses resulting from use in oil wells and to maintain a satisfactory, substantially fluid-tight jointunder these conditions. l

Objects, among others, of this invention are therefore to provide a lifting plunger or swab which is adapted to 'maintain a substantially fluid-tight connection with the interior surface of an oilfwell casing or cylinder of variable and imperfect mechanical construction, to provide a'swab packing protected against mutilation by the irregu arities of the interior surface of the well casing, and, in general, to improve upon the opera-` tive efficiency and durability of Vdevices of this character. For these purposes, in its more specific aspect, the present invention provides packing f members or swab Vcups which are formed with quite flexible or yieldable walls, being supported both at their upper and lower ends in such a manner that during the upward movement of the plunger the flexible .walls may be expanded outwardly to maintain yieldable engagement with the well casing, while during theA downwardY movement of the casing the cup tends to contract away from the walls ofthe casing, thus widths of the slots. A portion of a. cup of 1 192s. seriai No. 270,901.

and bruising action of the rough, imperfect- .55

lv formed surface of the well casing upon the expanded packing member, such material also being able to resist the chemical action of the various grades of Oil which are met in various localities and which cause deterioration of the conventional swab cup material.

lnthe accompanying drawings, which exemplify one embodiment of the invention: Y l is a view partially in elevation and partiallyin section illust-rating a swab con- Y structed in accordance with the present invention Fig. 2 is a side elevational vie/w of a spacer member adapted to engage the upper and lower portions of ,a swab cup; and

Fig. 3 is a View partially in section and partially in perspective of a portion of a packing member orcswab cup as it is preformed and before vit is assembled with the swab.

A swab of the character disclosed in the accompanying drawingsmay comprise a cenltral support or hollow plunger 1 which has a wei hted inlet valve 2 at its 'lower' end and out et ports 4 at its upper end, the entire assembly being adapted to be raised by avsuitable wire cable or the like (not shown). A plurality of packing members 6 are carried upon the swab to enable it tolift a quantity offluid during its upward movement.

Cups 6 preferably have walls formed of comparatively flexible, somewhat resilient material, certain types of leather being particularly suitable for this pur ose. The lower port-ions of the cups pre erably are preformed, Fig. 3, being` provided with a central opening 7 vand a dished or concavovconvexly curved portion 8 which merges into an upright wall 9. The upper edge ofl this wall preferably is broken up by a plurality '95 terminate in suitable circular openings 11 with diameters somewhat greater than the tom portion of the cup is substantially form retaining due to the manner of forming or pressing the material thereof, while each of the parallel upper extensions 22 of the cup wall may be comparatively flexible due to the slots 10 therebetween.

Cups or packing members of this character preferably are assembled upon the swab l by means of suitable anular retaining members which are secured or mounted upon thecentral support and designed to grip the upper and lower edges of the cup wall. For this purpose, I provide a lower annular ring 12 adapted to engage the' outer or bottom surface of the lower cup. Within each cup is located a suitable spacing member 14, shown in elevation in Fig. 2 and in section in Fig. 1. This spacing member preferably is provided with an outstandimr lower part 15 having corrugations 16 on itszlower surface. The intermediate body portion ofthe spacer 14 prefer ably is arranged to be in juxtaposed parallelism to the wall of the central support l, while its upper portion comprises an annular enlargement 17 having a surface 18 with a general upward inclination `toward the central axis of the support, this inclined surface also being provided with suitable corrugations 23. The lower ring 12 is adapted to clamp the dished lower portion of the lower packing element 6 against the lower part of a spacer 14, while rings 19 are disposed between adjoining packingcups, and a retaining ring 29 engages the upper art of the upper cup. The lower portion o each ring 19 and of member 29 may be provided with a downwardly inclined rabbet with a surface adapted to parallel the upper surface 18 of a spacer 14 and to clamp the upper projections 22 of a cup wall to such a surface. Each l ring 19 may also have an annular rabbet 20 paralleling the lower corrugated surface 16 of an adjoiningl spacer 14 and clamping the lower portion of the cup against the same.

Slots- 10 are arran ed to extend downwardly for a considera le distance below the upper retaining member for eachcup, and t-he lower portions of the slots and the openings 11 comprising fluid ports which, however, are located above the intermediate parts ofthe respective cups. Due to the dished formation originally imparted to the lower portion of the cups 6 and due to the inclination of the surface 18 of each spacer, the intermediate portion of each of the somewhat flexible walls 9 tends to be'curved outwardly. The portions 22 of the cup 10 are particularly -advantageous in supporting the upper edge thereof and in permitting the flexible cup wall to be retained in position under comparatively heavy loads and stresses;

In the use of a swab cup of the character disclosed, slots 10 and openings 1,1 are adapt` ed to receive fluid during the upward stroke of the plunger and to permit entrance of the same 'into the spacev about member 14 and within the cup.- Thus the intermediate portion of the wall of the latter is expanded and held against the inner face of the wall of well casing 21, the flexibility of the wall material, however, permitting it to conform in a' satisfactory manner to the imperfections of the surface with which it is in engagement andthe leather being particularly effective in withstandin abrasions by the surface. When the p unger lor swab is dropped downwardly in the opposite direction, the flexibil-v ible wall are clamped permits the cup to be formed of material having comparatively' yieldable or thin'walls,this material being unusually effective in withstandin wear and chemical deterioration'and in con orming to irregularities in the well casing as well as readilyV contracting upon the downward stroke. Furthermore, the spacer means and cooperating retaining rings permit the upperv and lower portions of the cup wall to be `firmly gripped and to be held in place despite the heavy loads placed thereon, such a firm gripping action being desirable due to the com arative flexibility of the cup wall itself. bviously. the arrangement of the openings or ports 11 in the cup wall not only ermits the upper portion of this wall formed y extensions 11 to be flexible and therefore readily bent inward to conform to the inclinationA of the retaining surfaces, but also affords conveniently disposed inlet ports in the cup wall itself without requiring provision for the same within the metal members or interfering wth the firm grip upon the sht material of the cup` wall itself. i

1. In a swab, a central support, a cup formed of flexible sheet material, means upon the support securing the upper and lower p0rtions o the cup wall to the support, the wall between said portions being spaced from the support, and lopen'ingsin'said cup wall near the upper portion thereof, said openings of the cup wall below edges ofthe cup wall to the support, the wall between said redges bein spaced from the support, openings in vsai cup wall and adv)oming the upper edge thereof, said o enupper and lower edges of the cup wall to the support, the wall between said edges being spaced from the support, and slots in said cup wall extending downwardl from the top edge. thereof, the lower en s of these slots,

providing openings which communicate with the spaceprovided between the same and the support.

4. n a swab, a central support, a swab cup disposed aboutsaid support, means upon the support enga 'ng the lower -portion of the cupsaid cup aving slots at its upper edge, means upon the support gripping and supporting the upper portions o the cup wall etween said supports, said slots 4extendin below said last-named means to provide fini openings.

5. In a swab, a central support, a swab cup disposed about said su port, said cup having a `iiexible wall of fi rous sheet material, means upon the support engaging the lower portion of the cup, said cup hav1ng-slots at its upper edge, means upon the support pping vand supporting the upper edge o the cup wall between said supports, said slots extending below said last-named means`to provide fluid openlngs, and retalning means arranged to hold the intermediate the wall spaced from the support.

6. A swab cup comprising'a sheet of/flexible fibrous material having a dished bottom portion with a central opening therein, said ottom portion merging into a wall/of substantially circular cross section, the upper part of said wall having a plurality of slots extending downwardly from its up .r edge, whereby the separate upper parts o the wall may have considerable iiexibilitypand may be bent inwardly to be held by Ia support extending through the central opening.

7. A swab cup comprising a sheet of ilexible fibrous material having a dished bottom portion with a central opening therein, said ottoni portion merging into an upper wall of substantially circular cross section, the upper part of said wall having a plurality ofslots extendingdownwardly from its upper edge, the lower ends of said slots terminating in round openings with a diameter portion of about said su somewhat greater than the width of the slots.

8. In a swab, a ycentral support, a cup formed of flexible sheet material and having a dished bottom portion with a central openin the upper part of said cup bein rovi ed with slots separating the cup wa liuto a plurality of flexlble members, said central, i

Vsupport extending through said opening, means carried by the support securing the dishedibottom portion of the cu thereto, the flexible members at the upper e ge of the cup wall being bent inwardly and means securing said members to the central support, the

intermediate art of the cup wall arated from t e support, the lower parts of said slots providing openings to rmit liquid to enter into the s ace between t e cup vwall and support to i ex. the former outwardly.

ing sep- In testimony whereof I ax my si nature. sa

GEORGE CHRIsTE oN. 

